Changes in the environmental temperature mediate oxidative stress state that affects the
survival rate of fishes. In general, stressors could affect directly as fish death or
indirectly through inhibiting immunity thus allowing pathogen invasion and disease
incidence. Rapid temperature fluctuations cause severe physiological stress on fish so
any temperature change affects the immune system. Fishes elicit generalized
physiological and immunological stress response against heat stress. As in other
vertebrates, this generalized stress response comprises physiological responses that are
common to a wide range of environmental, physical and biological stressors. This mini
review provides insight into the effect of heat stress on the fishes and the immune
response against heat stress.